Online Detectives Flourish in Boston Manhunt

The hunt for the bombers behind the deadly Boston Marathon attacks didn't take place only on the streets with professional police officers and SWAT teams.

SEATTLE: The hunt for the bombers behind the deadly Boston Marathon attacks didn't take place only on the streets with professional police officers and SWAT teams. In an era of digital interactivity, it also unfolded around the country from the desks of ordinary people.

Fueled by Twitter, online forums like Reddit and 4Chan, smartphones and relays of police scanners, thousands of people played armchair detective as police searched for men who turned out to be suspects Dzhokhar and Tamerlan Tsarnaev, ethnic Chechen brothers who had immigrated from southern Russia years ago.

But as amateur online sleuths began identifying possible culprits, people were wrongly accused or placed under suspicion by crowdsourcing. It showed the damage that digital investigators can cause and raised a question: In the social-media generation, what does law enforcement unleash when, by implication, it deputizes the public for help?

"The FBI kind of opened the door,'' said Hanson R. Hosein, director of the University of Washington Master of Communication in Digital Media program. "It was almost like it was put up as challenge to them, and they rose to it. ... They can be either really helpful or mob rule.''

The bombings have been the highest-profile case in which the public has joined an active investigation, using ever-evolving crowd-sourcing tools, showing the pitfalls and benefits of new technology. It's certainly not vigilantism, but it's not standard policing, either. It's perhaps something new - the law-enforcement equivalent of citizen journalism.

Reddit users began piecing together clues in the pictures and videos. They pointed out men who were wearing backpacks standing in the crowd. They looked at the straps of backpacks to compare with the one thought to have carried the bomb. They analyzed the bombs' blasts and people's gazes. In one particular photo thread, posted on imgur.com shortly after the bombing, a user attempted to pinpoint exactly where the bomb was placed.